The invention relates to a photovoltaic cell electrically contacted only at its back surface, the photovoltaic cell comprising a thin semiconductor lamina.
In conventional crystalline photovoltaic cells formed from silicon wafers, the cell is generally thicker than actually required by the device. Making a thinner crystalline cell using conventional methods can be difficult, as thin wafers are prone to breakage. A photovoltaic cell includes an emitter and a base; typically one of the emitter or the base is contacted at the light-facing surface, while the other is contacted at the opposite face. As will be described, methods of forming a thin photovoltaic cell may present challenges in making electrical contact to both the light-facing and back surfaces of the photovoltaic cell.
There is a need, therefore, for a thin photovoltaic cell where electrical contact to both the emitter and base regions is readily made.